When you're looking for insulation options for your home, you shouldn't dismiss the possibility of spray foam insulation as a solution. Before you invest in anything to improve your home's energy efficiency, there are a few things that you should understand.
Injection and Spray Foam Are Different
You might think that spray and injection foam applications are the same, but the truth is that they are slightly different. While both types of foam will expand to the same level, they do not do so at the same rate. Spray foam expands rapidly, filling the space quickly. While this is efficient, it can also add excess pressure inside the wall cavity. Injection foam, on the other hand, expands slower, taking several minutes instead of seconds. This results in less pressure inside the wall cavity and potentially a more even fill.
The Ratio Needs To Be Right
Using spray foam and foam injection insulation means having to get the ratio of the chemicals right. These insulation products are based on a chemical reaction, so the mix must be correct for the foam to actually set up the way that it is supposed to. If the mix is off, it will result in foam that is either too soft or crumbly. If you want to be sure that the foam is going to harden and stay intact, consider working with an insulation contractor who can use a foam spray rig that monitors the ratio and the application cycle. That way, the foam flow will be interrupted if the mix falls outside of the predetermined ratio.
You Need To Know The Thickness
Every type of spray foam is rated specifically for the thickness recommended by the manufacturer. Familiarize yourself with the guidelines for the product you're using so that you don't exceed that thickness in each pass. Otherwise, you'll risk weakening the structural integrity of the foam by spraying it too thin. In addition, spraying it too thick may actually cause excessive heat accumulation from the chemical reaction of the foam itself.
While the open-cell foams don't have the problem with heat accumulation, they do have a rapid expansion rate. That means that you'll want to apply less foam per treatment. That allows you to observe the space and add more gradually if necessary without risking any excess foam or unnecessary pressure.
Before you do any insulation work in your house, talk with your local insulation and construction contractor for more guidance.